فصلنامه لیزر در پزشکی
سال ششم شماره 2 (پیاپی 31، تابستان 1388)

Basal cell carcinoma (BCC) is the most common skin cancer. Photodynamic therapy (PDT) -as a novel, non-invasive therapeutic approach- may be considered a valuable strategy. This study was designed with the aim of the evaluation of efficacy of PDT in treatment of BCC. This was a clinical trial which was done on 28 patients with BCC. Patients were treated with ALAPDT for 1-6 sessions monthly and evaluated for clinical response, cosmetic results and probable side effects. From 28 lesions 82.1% had some response to PDT (32.1% complete response and 50% partial response). Cosmetic result was excellent or good in 77.5% of cases. In 92.8% of cases no or mild side effect was observed. Patients with positive history of radiotherapy had less response (p<0.05). No significant relation was found between patient’s age or sex, localization, diameter and type of BCC with clinical response. At 6 months, none of the lesions had recurrence. PDT would be a good therapeutic option in treatment of BCC -especially superficial type- with high efficacy and low side effect.

The human any one can be exposed to electromagneticfield produced by television, computer, MRI radiation and so on. Consideration of effect of electromagnetic field on various tissue especially folliculogenesis process is seemingly important. This study was focused on the effect of MRI radiation on folliculogenesis in adult rats. We used a MRI device that could produce 1.5 Tesla electromagnetic radiations, and chose 22 wistar rats as laboratory animal models. Rats were divided into two equal groups as followings: experimental group which exposed by MRI device with 1.5 Tesla electromagnetic radiation and RF radiation and control group which exposed by MRI device with 1.5 Tesla electromagnetic radiation and without RF radiation. Rats were housed at temperature (22-25C) and light (12 h light/12 h dark) controlled condition with standard rat chow and tap water. Afterwards the rats were anesthetized with ether and blood samples were obtained from cardiac chambers for the measurement of serum levels of FSH, LH, estrogen and progesterone using radioimmunoassay (RIA). Ovaries were then removed, fixed in 10% formalin and embedded in paraffin. Serial sections (5 μm thick) were prepared from both ovaries and stained using haematoxylin and eosin staining method. Diameter and weight of ovaries were also measured. In all sections, all follicles (primary, secondary and tertiary follicles) were counted. Statistical analysis was performed by T-test. The findings of the present study indicated that there was not a significant difference (P<0.5) in various groups in amount of progesterone, strogen, primary follicle, secondary follicle, graffian follicle, diameter and weight of ovaries but there was a significantly decrease (P<0.05) in amount of FSH and LH in experimental group ratio to control group. The electromagnetic radiations in MRI device are not able to damage folliculogenesis process in adult female rats. Reduction of LH an FSH in experimental group can be for animal position while they were exposed on radiation. Finally MRI radiation can be safe for folliculogenesis process in adult female rats.

Classification and evaluation of human skin color is necessary in both clinical and diagnostic applications, especially in determination of human skin type. In this paper, we present a new method for determination of quantitative characteristics of human skin pigmentations, Melanin and Hemoglobin, using spectrophotometric spectra. In the next stage, we classified these features based on their related skin color using three common classifiers: K- nearest neighborhood, Neural Network, and SVM. Classification results show that this method is able to classify skin color accurately and also can be used for classification of skin lesions based on their colors.

Laser hair removal application in dermatology has been a conventional method for many years. Many research projects have been performed for assessment and qualification of best results. We investigated the influence of long term follow up on therapeutic response rate. At a prospective study, 29 women referred to dermatologic clinic of Rasol Akram Hospital during 2002-2009, were enrolled. All of them were treated by a Long-pulsed 1064 nm ND:YAG laser. Clinical responses (hair reduction) were evaluated by a blinded dermatologist with comparing of before and after obtaining photographs according to visual analogue scale (VAS). Mean age of patients was 30.6± 8.5 years. Minimum and maximum sessions were 4 and 16. Mean of treatment sessions was 8.5 ± 2.8. Mean improvement at final treatment sessions and end of follow up were 72.3± 18.8 percent and 72.2 ± 22 percent, respectively. There was statistically significant correlation between first and final therapeutic response (p=0.001) and indicated final response at a long duration follow up (p=0.002). Our results showed that primary responses of hair removal by long pulsed Nd:YAG laser was an indicator for long term response rate.

Diabetes Mellitus is a common metabolic disorder around the world. Chronic foot ulcers are one of the debilitating complications in patients with diabetes. Several studies have shown that bacterial colonization and bacterial load can affect healing process in these patients. In this study, the effect of low level laser therapy on bacterial load of diabetic foot ulcers was evaluated.

In this pilot study, patients with stage I and II Wagner chronic diabetic foot ulcer (more than 3 months) were enrolled. Patients were randomly assigned in two laser and placebo groups. Laser parameters used in laser group were wavelength 670 nm, output power 30 mW, fluence 10 J/cm2. Bacterial load assessment was done through post debridement wound fluid collection. Three samples from 3 different sites of each wound were collected on day 0, 7, 14 after beginning of treatment.

Single and average intraclass correlation coefficients (ICC) for 32 samples were 0.7 and 0.873, respectively. There was no statistically significant difference between laser and placebo groups before and aftertwo week-treatment according to bacterial count.

Our findings showed that post-debridement wound fluid could be used asa reproducible and noninvasive method for detecting bacterial load accurately. Further studies are needed to evaluate the effect of low level laser therapy on growth of bacteria in clinical conditions.

Diabetic retinopathy by inducing macular edema and proliferative diabetic retinopathy, is the most prevalent cause of visual loss in developed countries. Also, it is one of the most frequent causes of legal blindness in developing countries. The effective role of laser treatment has been proven in major randomized clinical trials. Scatter panretinal photocoagulation (PRP) in eyes with proliferative diabetic retinopathy and high-risk characteristics, decreases the risk of visual loss in >50% of eyes. Also, scatter PRP may have some benefits in nonproliferative diabetic retinopathy. In clinically significant macular edema, focal laser photocoagulation decreases the risk of moderate visual loss up to 50%. In this article, we describe the laser photocoagulation technique and characteristics in the management of diabetic retinopathy.